Lloris returned to training having recovered from a thigh injury, that has seen him on the sidelines since the end of August, but Belgian duo Jan Vertonghen and Mousa Dembele, and Danish star Christian Eriksen have been ruled out of the game because of hamstring, thigh and abdomen injuries respectively.
England midfielder Dele Alli and Ivory Coast defender Serge Aurier are also unavailable because of hamstring and thigh problems.
"It is a period when we are not having good luck with injuries," said Pochettino.
"We are not victims though. We must feel strong. Every player must feel they can win and achieve what we want."
The quintet will also not be fit for the Premier League match with struggling Cardiff on Saturday.
"Hugo Lloris has returned to training and is available for selection ahead of Wednesday night's mouth-watering Champions League clash with Barcelona," read a club statement on their website.
"Ruled out are Dele Alli (hamstring), Serge Aurier (thigh), Mousa Dembele (thigh), Christian Eriksen (abdomen) and Jan Vertonghen (hamstring).
"The quintet will not be available before the international break."
Their absences couldn't have come at a worse time.
Pochettino's side can ill afford a damaging defeat against the Spanish champions after conceding two late goals to lose their opening Group B match 2-1 at Inter Milan.